An epidemiological survey of drug addiction in the Paris region included three studies which were carried out in 1981 and 1982. The first study of 100 clinical records revealed,
inter alia, that only a small proportion of drug addicts had been referred to the institution by parents, general practitioners and the medical and social services, while the majority of cases had decided spontaneously or in response to peer pressure to seek consultation. The second study, which concerned the latency time, showed that for the majority of addicts, less than three years elapsed between the first use of heroin and the first consultation and that, on average, one year elapsed between the time when the addict became aware of his or her dependence and the first consultation. The third study, which was ethnographic, indicated that the first request for treatment was most often not prompted by the onset of a physical disorder related to drug use or withdrawal but by a situation which involved a number of factors, particularly a feeling or being tired of drug addiction.

At present there are no means to evaluate the true extent of drug addiction in France : in particular, the number and basic profiles of drug addicts admitted to institutions providing treatment is not .known. The constant rise in deaths related to drug use and the enormous increase in heroin seizures lead the authors to think that drug abuse is assuming the dimensions of a serious epidemic. This indicates how necessary it is to evaluate the real extent of drug addiction in France and to distinguish its principal features, in order to propose suitable preventive measures and to make treatment more effective.

This is why, in 1981, the authors carried out an epidemiological study with the aim of making an initial assessment of the extent of drug addiction in the Paris region. The study used data collected in three treatment centres, ethnographic data gathered "on the street" and information from other sources such as general practitioners and the narcotics squad.

In assessing drug addiction the aim is to quantify it and ascertain its likely trends, in the medium term. Such an assessment should help to formulate health policy, particularly in regard to preventive work. The method used must be tailored to the specific features of drug addiction and the medical and legal status of drug addicts.

The method was therefore chosen with these requirements in mind. It was decided from the outset not to use the sampling method, either with the population at large or with a population of drug addicts admitted to treatment centres, since the resulting information would have been essentially narrow in focus and open to debate in that it would have taken into account only one, limited, aspect of drug addiction
[
[1]] .

For this reason, it was considered worthwhile to take into consideration a number of indirect indicators, in order to rearrange them and arrive at a synthesis. Among the indicators priority was given to the first request made by the addicts to the treatment centres. The authors believed that the first request was especially revealing, both from a quantitative and from a qualitative standpoint, of trends in drug addiction.

In three Paris treatment centres, the Marmottan and Fernand Widal Hospitals and the Charonne Association, the epidemiological form recommended by the World Health Organization was used
[
[2]] . The following information was collected in 1981 and 1982 : the age and sex of drug addicts ; the history of drug use ; and the frequency and method of drug use. Additional information included : the number of previous treatments, if any ; the date of the initial request for treatment ; the date when addicts first realized they were drug-dependent ; and the occupation.

Forms were filled out either after an interview or on the basis of the clinical record. In addition, semi-directive interviews made an in-depth analysis of the demand for treatment in two of the three institutions possible.

In addition, field study data was collected using the classic methods of ethnography. This enabled the authors, with the aid of the "snowball'' method
[
[3]] and participant observation
[
[4]] , to gather a great deal of information of a basically qualitative nature regarding the drug addicts' lifestyles, their relations with the treatment centres and the strategies that would make it possible to achieve some measure of control over drug dependence. It also enabled the authors to carry out quickly an epidemiological survey of a new pathology caused by
Candida albicans among heroin addicts
[
[5]] .

For the field study a truck was used for transport and as a mobile office. On a regular basis, 100 addicts, including both some who had and some who had not applied for treatment, were interviewed. Notes were taken at the interviews, and some were recorded and subsequently transcribed. Various aspects of drug-taking and in particular the ways in which heroin was distributed, were studied in order to make a comparison with earlier descriptions
[
[6]] - Cases of spontaneous detoxication were also studied, and an attempt was made to find a definition of drug dependence that took into account the economic constraints to which drug addicts are subject.

Finally, other data, in particular those of the narcotics squad, were taken into account.

Before finalizing the form, it was tried out in 1981 on 100 clinical records. The findings from this initial study showed a homogeneous population : the subjects were young; they were severely intoxicated (57 per cent) ; they were predominantly using one drug, heroin (93 per cent) ; and they had not had previous treatment (72 per cent). For both the boys (77 per cent) and the girls (22 per cent), this first request for treatment was linked to drug dependence and not to a critical accident, whether medical or social.

The factors that were directly responsible for leading the subjects to seek a consultation were analysed. Strangely enough, the patients had seldom been referred to the institution by parents, general practitioners and the medical and social services as a whole (l 5 per cent). In fact, in the majority of cases the decision to seek a consultation had been taken spontaneously or in response to peer pressure.

As a follow-up to these findings, a special study of the latency time - the time lapse between the first use of heroin and the first consultation - was made using the cases of 433 subjects requesting treatment for the first time.

The latency time was subdivided into two parts. To begin with, the time needed for the subjects to become aware of their condition of dependence was determined : this is the "dependence time''. Secondly, the time needed for the subjects to decide to seek a consultation was determined : this is the "request time". The distribution of these times proves to be highly significant and leads to the conclusion that the process of dependence is identical in all cases. For the majority of drug addicts, less than three years elapse between the first use of heroin and the first consultation ; on average, one year elapses between the time when the addict becomes aware of dependence and the first consultation. (See figure I.)

Time elapsed between the first use of heroin and the first consultation

Ages of persons requesting treatment for the first time, 1972

A comparison of the age distribution of the addicts requesting treatment for the first time indicates that, over a period of 10 years, the age pyramid became much broader : the heroin addicts of today can just as well begin their "careers" at 18 years of age as at 22 or 24 (figures II and III). This is a reflection of how very widespread heroin consumption is in France ; it is no longer the special preserve of adolescents. It will no doubt be valuable to monitor this distribution in future.

Ages of persons requesting treatment for the first time, 1982

Of particular concern were the life-styles of regular heroin users and their relationships with the treatment centres. One feature that seems to be fundamental to first requests addressed by drug addicts to treatment centres is that the first request does not appear to be the outcome of a long psychological process or precise motivation ; it is most often the result of an impulse : the subject "takes the plunge" as it were
[
[7]] . In general, family, medical or legal pressures were not cited as the reasons for this first step. Most often the step was not prompted by the onset of a physical disorder related to drug use or by an incident of withdrawal. In more than 70 per cent of the cases, the drug addicts referred to a situation that involved a number of factors and particularly a feeling of being tired of drug dependence. Finally, peer-group pressure was very widely noted leading to the conclusion that such pressure makes itself felt indirectly when the subject is no longer able to maintain his or her position in the group owing to psychological or financial difficulties.

Interviews and personal observations were used to distinguish current trends in the abuse and distribution of substances. It emerged that heroin is widely available. According to informants, a fair proportion of cannabis traffickers have converted to heroin selling. Heroin is no longer sold only in the street ; there has been an increasing trend, since I 980, for it to be sold in apartments set aside for that purpose. Finally - and this is undoubtedly one of the indicators of an epidemic - most of the heroin pushers are young and do not belong to the traditional heroin-traffic milieu. In three years there has been little change in the price of heroin, which still retails at about 800 francs per gram.

As far as other substances are concerned, cocaine use seems to have become more widespread ; cocaine now retails at around 600 francs per gram. Cannabis use is not increasing. On the other hand, there is a marked upward trend in the use of organic solvents and LSD, particularly among adolescents.

The validity of each of the indicators chosen must first be discussed.

While statistics on the first request made to a treatment centre are used to measure the incidence of drug addiction, they also measure a certain threshold of tolerance in a given population
[
[8]] with respect to a form of deviant behaviour. Moreover, each treatment centre has a certain image, and in this way there is a selection process in each institution with regard to the population received.

The figures obtained from the narcotics squad must also be carefully interpreted, in so far as they can be affected by numerous factors specific to police operations.

Lastly, it cannot be pretended that the field study data are based on a representative sample, if indeed that term can be considered meaningful in the context of drug addiction. However, the study outlined here falls within the traditional framework of epidemiology ; this entails looking at the phenomenon of drug addiction from a multi-disciplinary standpoint rather than solely from a medical perspective. The authors think that the anthropological point of view is the best stimulus to future research, reflected in the work carried out by E, Preble
[
[6]] and A. Lindesmith
[
[9]] .

Thus, micro-epidemiological studies are important to the authors, as such studies permit an inquiry into the significance to be accorded to findings that have yet to be adequately explained, such as repeated requests for treatment, spontaneous cures and, lastly, the curious relationship between drug addicts and the world of medicine.

Finally, the authors maintain that the findings presented here are still fragmentary and do not allow a description of the phenomenon as a whole, but they are confident that a quantitative assessment of drug dependence cannot be dissociated from theoretical research in the field of the human sciences and that the way to achieve a synthesis is through a complementary analysis of the various findings.